An Anisotropic Effective Model for the Simulation of Semiflexible Ring Polymers

TL;DR

This paper develops an anisotropic coarse-grained model for semiflexible ring polymers, capturing their structural features more accurately than isotropic models, especially for short and intermediate lengths.

Contribution

It introduces a novel anisotropic effective pair potential approach for simulating semiflexible ring polymers, improving upon previous isotropic models.

Findings

The model accurately reproduces structural features of short and intermediate rings.

It fails to capture behavior of large, flexible rings at high densities.

The approach provides a physical basis for anisotropic penetrable interactions.

Abstract

We derive and introduce anisotropic effective pair potentials to coarse-grain solutions of semiflexible rings polymers of various lengths. The system has been recently investigated by means of full monomer-resolved computer simulations, revealing a host of unusual features and structure formation, which, however, cannot be captured by a rotationally-averaged effective pair potential between the rings' centers of mass [M. Bernabei et al., Soft Matter 9, 1287 (2013)]. Our new coarse-graining strategy is to picture each ring as a soft, penetrable disc. We demonstrate that for the short- and intermediate-length rings the new model is quite capable of capturing the Physics in a quantitative fashion, whereas for the largest rings, which resemble flexible ones, it fails at high densities. Our work opens the way for the physical justification of general, anisotropic penetrable interaction potentials.